There are instances of erectile impotence in which the patient does not respond to more conventional therapy, and the surgical implanting of a penile prosthesis is the only practical means of remedying the impotency.
In the past, several types of implantable penile prostheses have been employed. The first and most common type is a pair of identical semi-rigid rods of suitable stiffness. Each of the rods is surgically implanted into a corpus cavernosum of the penis. The implants disclosed in U.S. Pat. Nos. 3,853,122 and 4,066,073 are representative of this type of penile prosthesis.
Another type of penile prosthesis which is available is the inflatable prosthesis. The most common inflatable prosthesis includes a pair of fairly long inflatable and expandable tubes. Each of the tubes is surgically implanted in a corpus cavernosum of the penis. The two tubes are connected by tubing to a pressure bulb of inflating fluid which is implanted elsewhere in the body. Because of the volume required to pressurize, inflate and expand the inflatable tubes, the pressure bulbs are relatively large. For example, in U.S. Pat. No. 3,954,102, an inflatable prosthesis is disclosed in which the fluid is supplied from a single relatively large reservoir which is implanted in the abdominal cavity. The prosthesis of U.S. Pat. No. 4,009,711 includes two implants each having its own relatively large pressurizing bulb which is surgically implanted in the scrotal sac.
The inflatable type implant has an advantage over the semi-rigid rod implant in that its size can be increased to provide a more natural erection. On the other hand, the semi-rigid rod implant is more dependable as the inflatable type can develop leaks.
In U.S. Pat. No. 4,201,202 an implant is disclosed which is a combination semi-rigid rod and inflatable prosthesis. The prosthesis consists of a pair of rods, preferably of the type disclosed in U.S. Pat. No. 4,066,073, which have a flexible sleeve positioned and sealed axially about an intermediate portion of the rod to form a chamber for pressurizing fluid. Each of the implants has a pressure bulb of pressurizing fluid connected by tubing to the chamber so that it can be pressurized and also a valve to depressurize the chamber. A penile erection is achieved by either pressurizing the chambers if a soft rod is used or by manually moving the implants to an erect position if a stiffer hinged rod is used. The implant has an advantage over the conventional semi-rigid rod implant in that the chamber can be pressurized to increase penile girth.